558  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1904.  [bull.  260. 
It  closely  resembles  kaolin  and  has  doubtless  been  derived  from  a 
granite  or  other  rock  containing  much  feldspar.  The  clay  bed  being 
worked  lies  about  one-half  mile  from  Palouse  River.  It  has  a  thick- 
ness varying  from  15  to  20  feet  and  is  overlain  by  10  to  15  feet  of 
soil.  The  clay  is  mostly  white,  soft,  fine  grained,  and  free  from  grit. 
It  has  a  greasy  feel,  is  ver}^  plastic,  and  when  placed  in  water  slakes 
rapidly.  The  clay  is  used  chiefly  in  the  manufacture  of  stoneware 
at  the  plant  of  the  Palouse  Pottery  Company. 
Yakima  County. — Alluvial  deposits  of  clay  occur  in  the  valley  of 
Yakima  River  near  North  Yakima.  The  bed  of  clay  that  has  been 
opened  up  is  only  about  3  feet  in  thickness.  It  lies  at  the  surface 
and  is  underlain  by  beds  of  coarse  gravels  and  bowlders.  The  clay 
is  dark  brown  and  contains  much  vegetable  matter.  It  is  sandy, 
soft,  and  incoherent,  and  can  be  used  only  in  the  manufacture  of 
common  brick. 
